* [PATCH] i2c: designware: Get right data length
@ 2021-02-25 2:35 Liguang Zhang
2021-02-25 11:19 ` Andy Shevchenko
0 siblings, 1 reply; 3+ messages in thread
From: Liguang Zhang @ 2021-02-25 2:35 UTC (permalink / raw)
To: Jarkko Nikula, Andy Shevchenko, Mika Westerberg, Philipp Zabel
Cc: linux-i2c, linux-kernel, Liguang Zhang
IC_DATA_CMD[11] indicates the first data byte received after the address
phase for receive transfer in Master receiver or Slave receiver mode,
this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the
data to be transmitted or received on the I2C bus, so we should use the
lower 8 bits to get the right data length.
Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
---
drivers/i2c/busses/i2c-designware-master.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index d6425ad6e6a3..c3cf76f6c607 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
/* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN &&
- tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
+ (tmp & 0xff) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
len = i2c_dw_recv_len(dev, tmp);
}
*buf++ = tmp;
--
2.19.1.6.gb485710b
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] i2c: designware: Get right data length
2021-02-25 2:35 [PATCH] i2c: designware: Get right data length Liguang Zhang
@ 2021-02-25 11:19 ` Andy Shevchenko
2021-02-25 14:06 ` 乱石
0 siblings, 1 reply; 3+ messages in thread
From: Andy Shevchenko @ 2021-02-25 11:19 UTC (permalink / raw)
To: Liguang Zhang
Cc: Jarkko Nikula, Mika Westerberg, Philipp Zabel, linux-i2c, linux-kernel
On Thu, Feb 25, 2021 at 10:35:28AM +0800, Liguang Zhang wrote:
> IC_DATA_CMD[11] indicates the first data byte received after the address
> phase for receive transfer in Master receiver or Slave receiver mode,
> this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the
> data to be transmitted or received on the I2C bus, so we should use the
> lower 8 bits to get the right data length.
Thanks for the report and fix!
My comments below.
> Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
> ---
> drivers/i2c/busses/i2c-designware-master.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
> index d6425ad6e6a3..c3cf76f6c607 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
> regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
> /* Ensure length byte is a valid value */
> if (flags & I2C_M_RECV_LEN &&
> - tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
> + (tmp & 0xff) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
Can we rather describe this as
#define DW_IC_DATA_CMD_DAT GENMASK(7, 0)
in *.h file and...
(tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
...here?
> len = i2c_dw_recv_len(dev, tmp);
> }
> *buf++ = tmp;
> --
> 2.19.1.6.gb485710b
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] i2c: designware: Get right data length
2021-02-25 11:19 ` Andy Shevchenko
@ 2021-02-25 14:06 ` 乱石
0 siblings, 0 replies; 3+ messages in thread
From: 乱石 @ 2021-02-25 14:06 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Jarkko Nikula, Mika Westerberg, Philipp Zabel, linux-i2c, linux-kernel
Hi,
在 2021/2/25 19:19, Andy Shevchenko 写道:
> On Thu, Feb 25, 2021 at 10:35:28AM +0800, Liguang Zhang wrote:
>> IC_DATA_CMD[11] indicates the first data byte received after the address
>> phase for receive transfer in Master receiver or Slave receiver mode,
>> this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the
>> data to be transmitted or received on the I2C bus, so we should use the
>> lower 8 bits to get the right data length.
> Thanks for the report and fix!
> My comments below.
Thanks for your comments. I will optimize my code follow your comments
and send v2 revision.
Regards,
Liguang
>
>> Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
>> ---
>> drivers/i2c/busses/i2c-designware-master.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
>> index d6425ad6e6a3..c3cf76f6c607 100644
>> --- a/drivers/i2c/busses/i2c-designware-master.c
>> +++ b/drivers/i2c/busses/i2c-designware-master.c
>> @@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
>> regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
>> /* Ensure length byte is a valid value */
>> if (flags & I2C_M_RECV_LEN &&
>> - tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
>> + (tmp & 0xff) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
> Can we rather describe this as
>
> #define DW_IC_DATA_CMD_DAT GENMASK(7, 0)
>
> in *.h file and...
>
> (tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
> ...here?
>
>> len = i2c_dw_recv_len(dev, tmp);
>> }
>> *buf++ = tmp;
>> --
>> 2.19.1.6.gb485710b
>>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-02-25 14:08 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-25 2:35 [PATCH] i2c: designware: Get right data length Liguang Zhang
2021-02-25 11:19 ` Andy Shevchenko
2021-02-25 14:06 ` 乱石
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).